a. Field of the Invention
The invention relates to an edge-lighting type backlight module.
b. Description of the Related Art
FIG. 4 shows a schematic diagram of a conventional edge-lighting type backlight module. Referring to FIG. 4, the edge-lighting type backlight module 100 includes a light guide plate 102, a light source module 104, and a back plate 106. The light source module 104 is disposed inside the back plate 106, and the heat generated by the light source module 104 is directly conducted to the back plate 106 and then gradually dissipated in the atmosphere. Beside, fin structures 108 are formed on an outer side of the back plate 106 to increase heat-dissipating areas. However, in the above design, the heat is gradually dissipated in the atmosphere through the back plate 106, the back plate 106 with large size is liable to twist or deform as a result of a thermal stress caused by non-uniform temperature distribution, and hence poor optical performance is given. Accordingly, some designs are proposed to solve this problem. For example, Taiwan patent publication No. 200516316 discloses a backlight module, wherein a thermal insulating spacer is disposed between a mask and an optical film to prevent the heat generated by a light-emitting device from transferring to the optical film. Besides, Taiwan patent No. M351370 discloses a backlight module, wherein an air gap exists between a reflective sheet and a back plate to prevent the heat generated by a light-emitting device from transferring to the reflective sheet or an optical film set.
However, the above designs fail to both provide good heat-dissipation efficiency and prevent heat from transferring to the back plate.